The invention is based on a device for mixing liquids by adjusting a mixing liquid mixing faucet, as generically defined hereinafter.
Mixing faucets for mixing liquids are known in many forms, as are methods for adjusting the movable valve members, of such mixing faucets; the mixing of liquids takes place when via at least two inflow lines of the mixing faucet, liquids that differ in temperature or type are supplied, and these liquids are then mixed within the faucet and supplied to the user in the form of a liquid mixture via at least one outflow line.
The quantity of a given liquid supplied to the mixture depends on the one hand on the control cross sections via which the particular liquid is delivered to the mixing faucet, and on the quantity drawn by the user, and on the other hand on the pressures of the inflowing liquids and the backup pressure on the consumer side.
The invention does not relate to mixing valve sets in which a constant pressure or flow rate is maintained by differently controlled cross sections (U.S. Pat. No. 3,038,496), nor to mixing faucets that operate only with a spool valve or the like, but rather pertains solely to mixing faucets in which via the movable valve members, the liquid streams supplied are determined independently of one another by means of the flow cross sections controlled by the movable valve members (International reference WO, A 82/02101). Typically these are valves in which the movable valve member is actuated via a screw-like mechanism (worm) via a valve shaft from outside the valve. A typical mixing faucet is for example the inflow set for a bathtub, in which cold and hot water are mixed together by varying the respective inflow cross sections and then flow out into the tub virtually without resistance.
However, mixing faucets also exist in which two movable valve members are disposed on one shaft, so that upon displacement of the shaft, which may for instance once again be effected via a worm and by rotation from outside the valve, one inflow cross section is narrowed while the other is enlarged in the same proportion. Unlike the bathtub faucet, in this case the association of the characteristic curves of the two valves is fixed and is not variable. A disadvantage, then, however, is that the flow quantity is likewise fixed; that is, the total cross section of the two inflows is divided between the two inflow cross sections depending on the location of the adjusting shaft, so that the range of usage is greatly restricted; for instance, it can be used only as a mixing valve in heating systems, or as a pressure-operated valve in a domestic or industrial hot-water system.